TR2017-006

Novel Baseband Equivalent Models of Quadrature Modulated All-Digital Transmitters


    •  Tanovic, O., Ma, R., Teo, K.H., "Novel Baseband Equivalent Models of Quadrature Modulated All-Digital Transmitters", IEEE Radio Wireless Week (RWW), January 2017.
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      • @article{Tanovic2017jan,
      • author = {Tanovic, Omer and Ma, Rui and Teo, Koon Hoo},
      • title = {Novel Baseband Equivalent Models of Quadrature Modulated All-Digital Transmitters},
      • journal = {IEEE Radio Wireless Week (RWW)},
      • year = 2017,
      • month = jan,
      • url = {https://www.merl.com/publications/TR2017-006}
      • }
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  • Research Area:

    Electric Systems


In this paper an exact baseband equivalent model of a quadrature modulated all-digital transmitter is derived. No restrictions on the number of levels of a digital switched-mode power amplifier (SMPA) driving input, nor the pulse encoding scheme employed, are made. This implies a high level of generality of the proposed model. We show that all-digital transmitter (ADT) can be represented as a series connection of the pulse encoder, discrete-time Volterra series model of fixed degree and memory depth, and a linear timevarying system with special properties. This result suggests a new analytically motivated structure of a digital predistortion (DPD) of SMPA nonlinearities in ADT. Numerical simulations in MATLAB are used to verify proposed baseband equivalent model.